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154 lines
3.7 KiB
154 lines
3.7 KiB
// SPDX-License-Identifier: GPL-2.0 |
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/* Copyright (c) 2020 Cloudflare Ltd https://cloudflare.com */ |
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#include <linux/skmsg.h> |
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#include <net/sock.h> |
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#include <net/udp.h> |
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#include <net/inet_common.h> |
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#include "udp_impl.h" |
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static struct proto *udpv6_prot_saved __read_mostly; |
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static int sk_udp_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, |
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int noblock, int flags, int *addr_len) |
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{ |
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#if IS_ENABLED(CONFIG_IPV6) |
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if (sk->sk_family == AF_INET6) |
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return udpv6_prot_saved->recvmsg(sk, msg, len, noblock, flags, |
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addr_len); |
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#endif |
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return udp_prot.recvmsg(sk, msg, len, noblock, flags, addr_len); |
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} |
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static bool udp_sk_has_data(struct sock *sk) |
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{ |
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return !skb_queue_empty(&udp_sk(sk)->reader_queue) || |
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!skb_queue_empty(&sk->sk_receive_queue); |
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} |
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static bool psock_has_data(struct sk_psock *psock) |
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{ |
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return !skb_queue_empty(&psock->ingress_skb) || |
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!sk_psock_queue_empty(psock); |
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} |
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#define udp_msg_has_data(__sk, __psock) \ |
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({ udp_sk_has_data(__sk) || psock_has_data(__psock); }) |
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static int udp_msg_wait_data(struct sock *sk, struct sk_psock *psock, |
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long timeo) |
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{ |
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DEFINE_WAIT_FUNC(wait, woken_wake_function); |
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int ret = 0; |
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if (sk->sk_shutdown & RCV_SHUTDOWN) |
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return 1; |
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if (!timeo) |
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return ret; |
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add_wait_queue(sk_sleep(sk), &wait); |
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sk_set_bit(SOCKWQ_ASYNC_WAITDATA, sk); |
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ret = udp_msg_has_data(sk, psock); |
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if (!ret) { |
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wait_woken(&wait, TASK_INTERRUPTIBLE, timeo); |
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ret = udp_msg_has_data(sk, psock); |
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} |
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sk_clear_bit(SOCKWQ_ASYNC_WAITDATA, sk); |
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remove_wait_queue(sk_sleep(sk), &wait); |
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return ret; |
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} |
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static int udp_bpf_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, |
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int nonblock, int flags, int *addr_len) |
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{ |
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struct sk_psock *psock; |
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int copied, ret; |
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if (unlikely(flags & MSG_ERRQUEUE)) |
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return inet_recv_error(sk, msg, len, addr_len); |
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psock = sk_psock_get(sk); |
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if (unlikely(!psock)) |
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return sk_udp_recvmsg(sk, msg, len, nonblock, flags, addr_len); |
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if (!psock_has_data(psock)) { |
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ret = sk_udp_recvmsg(sk, msg, len, nonblock, flags, addr_len); |
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goto out; |
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} |
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msg_bytes_ready: |
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copied = sk_msg_recvmsg(sk, psock, msg, len, flags); |
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if (!copied) { |
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long timeo; |
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int data; |
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timeo = sock_rcvtimeo(sk, nonblock); |
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data = udp_msg_wait_data(sk, psock, timeo); |
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if (data) { |
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if (psock_has_data(psock)) |
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goto msg_bytes_ready; |
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ret = sk_udp_recvmsg(sk, msg, len, nonblock, flags, addr_len); |
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goto out; |
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} |
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copied = -EAGAIN; |
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} |
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ret = copied; |
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out: |
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sk_psock_put(sk, psock); |
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return ret; |
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} |
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enum { |
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UDP_BPF_IPV4, |
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UDP_BPF_IPV6, |
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UDP_BPF_NUM_PROTS, |
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}; |
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static DEFINE_SPINLOCK(udpv6_prot_lock); |
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static struct proto udp_bpf_prots[UDP_BPF_NUM_PROTS]; |
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static void udp_bpf_rebuild_protos(struct proto *prot, const struct proto *base) |
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{ |
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*prot = *base; |
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prot->close = sock_map_close; |
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prot->recvmsg = udp_bpf_recvmsg; |
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} |
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static void udp_bpf_check_v6_needs_rebuild(struct proto *ops) |
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{ |
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if (unlikely(ops != smp_load_acquire(&udpv6_prot_saved))) { |
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spin_lock_bh(&udpv6_prot_lock); |
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if (likely(ops != udpv6_prot_saved)) { |
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udp_bpf_rebuild_protos(&udp_bpf_prots[UDP_BPF_IPV6], ops); |
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smp_store_release(&udpv6_prot_saved, ops); |
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} |
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spin_unlock_bh(&udpv6_prot_lock); |
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} |
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} |
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static int __init udp_bpf_v4_build_proto(void) |
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{ |
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udp_bpf_rebuild_protos(&udp_bpf_prots[UDP_BPF_IPV4], &udp_prot); |
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return 0; |
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} |
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late_initcall(udp_bpf_v4_build_proto); |
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int udp_bpf_update_proto(struct sock *sk, struct sk_psock *psock, bool restore) |
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{ |
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int family = sk->sk_family == AF_INET ? UDP_BPF_IPV4 : UDP_BPF_IPV6; |
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if (restore) { |
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sk->sk_write_space = psock->saved_write_space; |
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WRITE_ONCE(sk->sk_prot, psock->sk_proto); |
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return 0; |
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} |
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if (sk->sk_family == AF_INET6) |
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udp_bpf_check_v6_needs_rebuild(psock->sk_proto); |
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WRITE_ONCE(sk->sk_prot, &udp_bpf_prots[family]); |
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return 0; |
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} |
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EXPORT_SYMBOL_GPL(udp_bpf_update_proto);
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